diff --git a/p1am/defines.go b/p1am/defines.go
new file mode 100644
index 0000000..6699522
--- /dev/null
+++ b/p1am/defines.go
@@ -0,0 +1,157 @@
+package p1am
+
+//go:generate go run ./internal/cmd/gen_defines
+
+type ModuleProps struct {
+	ModuleID                                 uint32
+	DI, DO, AI, AO, Status, Config, DataSize byte
+	Name                                     string
+}
+
+var modules = []ModuleProps{
+	//{0x000000ID,di,do,ai,ao,st,cf,ds}
+	{0x00000000, 0, 0, 0, 0, 0, 0, 0, "Empty"}, //Empty first entry for defaultgs
+
+	{0x04A00081, 1, 0, 0, 0, 0, 0, 1, "P1-08ND3"}, //P1-08ND3
+
+	{0x04A00085, 1, 0, 0, 0, 0, 0, 1, "P1-08NA"}, //P1-08NA
+
+	{0x04A00087, 1, 0, 0, 0, 0, 0, 1, "P1-08SIM"}, //P1-08SIM
+
+	{0x04A00088, 1, 0, 0, 0, 0, 0, 1, "P1-08NE3"}, //P1-08NE3
+
+	{0x05200082, 2, 0, 0, 0, 0, 0, 1, "P1-16ND3"}, //P1-16ND3
+
+	{0x05200089, 2, 0, 0, 0, 0, 0, 1, "P1-16NE3"}, //P1-16NE3
+
+	{0x1403F481, 0, 0, 0, 32, 4, 4, 0xA0, "P1-04PWM"}, //P1-04PWM
+
+	{0x1404008D, 0, 1, 0, 0, 0, 0, 1, "P1-08TA"}, //P1-08TA
+
+	{0x1404008F, 0, 1, 0, 0, 0, 0, 1, "P1-08TRS"}, //P1-08TRS
+
+	{0x14040091, 0, 2, 0, 0, 0, 0, 1, "P1-16TR"}, //P1-16TR
+
+	{0x14050081, 0, 1, 0, 0, 0, 0, 1, "P1-08TD1"}, //P1-08TD1
+
+	{0x14050082, 0, 1, 0, 0, 0, 0, 1, "P1-08TD2"}, //P1-08TD2
+
+	{0x14080085, 0, 2, 0, 0, 0, 0, 1, "P1-15TD1"}, //P1-15TD1
+
+	{0x14080086, 0, 2, 0, 0, 0, 0, 1, "P1-15TD2"}, //P1-15TD2
+
+	{0x24A50081, 1, 1, 0, 0, 0, 0, 1, "P1-16CDR"}, //P1-16CDR
+
+	{0x24A50082, 1, 1, 0, 0, 0, 0, 1, "P1-15CDD1"}, //P1-15CDD1
+
+	{0x24A50083, 1, 1, 0, 0, 0, 0, 1, "P1-15CDD2"}, //P1-15CDD2
+
+	{0x34605581, 0, 0, 16, 0, 12, 18, 16, "P1-04AD"}, //P1-04AD
+
+	{0x34605588, 0, 0, 16, 0, 12, 8, 16, "P1-04RTD"}, //P1-04RTD
+
+	{0x3460558F, 0, 0, 16, 0, 12, 2, 12, "P1-04ADL-1"}, //P1-04ADL-1
+
+	{0x34605590, 0, 0, 16, 0, 12, 2, 12, "P1-04ADL-2"}, //P1-04ADL-2
+
+	{0x34608C81, 0, 0, 16, 0, 12, 20, 32, "P1-04THM"}, //P1-04THM
+
+	{0x34608C8E, 0, 0, 16, 0, 12, 8, 32, "P1-04NTC"}, //P1-04NTC
+
+	{0x34A0558A, 0, 0, 32, 0, 12, 2, 12, "P1-08ADL-1"}, //P1-08ADL-1
+
+	{0x34A0558B, 0, 0, 32, 0, 12, 2, 12, "P1-08ADL-2"}, //P1-08ADL-2
+
+	{0x34A5A481, 2, 0, 36, 36, 4, 12, 0xC0, "P1-02HSC"}, //P1-02HSC
+
+	{0x44035583, 0, 0, 0, 16, 4, 0, 12, "P1-04DAL-1"}, //P1-04DAL-1
+
+	{0x44035584, 0, 0, 0, 16, 4, 0, 12, "P1-04DAL-2"}, //P1-04DAL-2
+
+	{0x44055588, 0, 0, 0, 32, 4, 0, 12, "P1-08DAL-1"}, //P1-08DAL-1
+
+	{0x44055589, 0, 0, 0, 32, 4, 0, 12, "P1-08DAL-2"}, //P1-08DAL-2
+
+	{0x5461A783, 0, 0, 16, 8, 12, 2, 12, "P1-4ADL2DAL-1"}, //P1-4ADL2DAL-1
+
+	{0x5461A784, 0, 0, 16, 8, 12, 2, 12, "P1-4ADL2DAL-2"}, //P1-4ADL2DAL-2
+
+	{0xFFFFFFFF, 0, 0, 0, 0, 0, 0, 0, "BAD SLOT"}, //empty in case no modules are defined.
+
+	{0x00000000, 0, 0, 0, 0, 0, 0, 0, "BAD SLOT"}, //empty in case no modules are defined.
+}
+
+var defaultConfig = map[uint32][]byte{
+	0x34605590:// P1_04ADL_2_DEFAULT_CONFIG
+	{0x40, 0x03},
+	0x34608C8E: // P1_04NTC_DEFAULT_CONFIG
+	{0x40, 0x03, 0x60, 0x05,
+		0x20, 0x00, 0x80, 0x02},
+	0x34608C81: // P1_04THM_DEFAULT_CONFIG
+	{0x40, 0x03, 0x60, 0x05,
+		0x21, 0x00, 0x22, 0x00,
+		0x23, 0x00, 0x24, 0x00,
+		0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00},
+	0x34605588: // P1_04RTD_DEFAULT_CONFIG
+	{0x40, 0x03, 0x60, 0x05,
+		0x20, 0x01, 0x80, 0x00},
+	0x34605581: // P1_04AD_DEFAULT_CONFIG
+	{0x40, 0x03, 0x00, 0x00,
+		0x20, 0x03, 0x00, 0x00,
+		0x21, 0x03, 0x00, 0x00,
+		0x22, 0x03, 0x00, 0x00,
+		0x23, 0x03},
+	0x3460558F:// P1_04ADL_1_DEFAULT_CONFIG
+	{0x40, 0x03},
+	0x34A0558A:// P1_08ADL_1_DEFAULT_CONFIG
+	{0x40, 0x07},
+	0x34A0558B:// P1_08ADL_2_DEFAULT_CONFIG
+	{0x40, 0x07},
+	0x5461A783:// P1_04ADL2DAL_1_DEFAULT_CONFIG
+	{0x40, 0x03},
+	0x5461A784:// P1_04ADL2DAL_2_DEFAULT_CONFIG
+	{0x40, 0x03},
+	0x1403F481:// P1_04PWM_DEFAULT_CONFIG
+	{0x02, 0x02, 0x02, 0x02},
+	0x34A5A481: // P1_02HSC_DEFAULT_CONFIG
+	{0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x01,
+		0x00, 0x00, 0x00, 0x01},
+}
+
+const NUMBER_OF_MODULES = 15 //Current max 15 Modules
+const SWITCH_BUILTIN = 31
+const baseEnable = 33
+const MOD_HDR = 0x02
+const VERSION_HDR = 0x03
+const ACTIVE_HDR = 0x04
+const DROPOUT_HDR = 0x05
+const CFG_HDR = 0x10
+const READ_CFG_HDR = 0x11
+const PETWD_HDR = 0x30
+const STARTWD_HDR = 0x31
+const STOPWD_HDR = 0x32
+const CONFIGWD_HDR = 0x33
+const READ_STATUS_HDR = 0x40
+const READ_DISCRETE_HDR = 0x50
+const READ_ANALOG_HDR = 0x51
+const READ_BLOCK_HDR = 0x52
+const WRITE_DISCRETE_HDR = 0x60
+const WRITE_ANALOG_HDR = 0x61
+const WRITE_BLOCK_HDR = 0x62
+const FW_UPDATE_HDR = 0xAA
+const DUMMY = 0xFF
+const EMPTY_SLOT_ID = 0xFFFFFFFE
+const MAX_TIMEOUT = 0xFFFFFFFF
+const DISCRETE_IN_BLOCK = 0
+const ANALOG_IN_BLOCK = 1
+const DISCRETE_OUT_BLOCK = 2
+const ANALOG_OUT_BLOCK = 3
+const STATUS_IN_BLOCK = 4
+const MISSING24V_STATUS = 3
+const BURNOUT_STATUS = 5
+const UNDER_RANGE_STATUS = 7
+const OVER_RANGE_STATUS = 11
+const TOGGLE = 0x01
+const HOLD = 0x00
diff --git a/p1am/internal/cmd/gen_defines/main.go b/p1am/internal/cmd/gen_defines/main.go
new file mode 100644
index 0000000..881d1ed
--- /dev/null
+++ b/p1am/internal/cmd/gen_defines/main.go
@@ -0,0 +1,133 @@
+package main
+
+import (
+	"bytes"
+	"go/format"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"text/template"
+)
+
+var tmpl = template.Must(template.New("main").Parse(`package p1am
+
+//go:generate go run ./internal/cmd/gen_defines
+
+type ModuleProps struct {
+	ModuleID                                 uint32
+	DI, DO, AI, AO, Status, Config, DataSize byte
+	Name                                     string
+}
+
+var modules = []ModuleProps{
+{{.MDB -}}
+}
+
+var defaultConfig = map[uint32][]byte{
+	{{range .Configs -}}
+	0x{{.ID}}: // {{.Name}}
+	{{index $.DefaultConfigs .Name}},
+	{{end}}
+}
+
+{{range .Defines}}
+const {{.Name}} = {{.Value}}{{.Comment -}}
+{{end}}
+`))
+
+func findLibrary() string {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		log.Fatal(err)
+	}
+	for _, dir := range []string{
+		"Documents/Arduino",
+		"Arduino",
+	} {
+		dir = filepath.Join(home, dir, "libraries/P1AM/src")
+		if _, err := os.Stat(dir); err == nil {
+			return dir
+		}
+	}
+	return ""
+}
+
+func definitions(path string, delim string) []string {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return strings.Split(string(data), delim)
+}
+
+var (
+	mdbRE    = regexp.MustCompile(`(?s)mdb\[\] = \{\s*(.+)\}`)
+	configRE = regexp.MustCompile(`(?s)const char (.*?)\[\] = (.+)`)
+	caseRE   = regexp.MustCompile(`(?s)case 0x([^:]+):\s+return \(char\*\)(.+)`)
+	defineRE = regexp.MustCompile(`(?ms)^\s*#define (\S+)\s+(\d+|0x[0-9a-fA-F]+)(\s+.*?)?\s*$`)
+)
+
+func main() {
+	base := findLibrary()
+	if base == "" {
+		log.Fatal("can't find Arduino library")
+	}
+	var data = struct {
+		MDB            string
+		DefaultConfigs map[string]string
+		Configs        []struct {
+			ID   string
+			Name string
+		}
+		Defines []struct {
+			Name    string
+			Value   string
+			Comment string
+		}
+	}{
+		DefaultConfigs: make(map[string]string),
+	}
+	for _, line := range definitions(filepath.Join(base, "Module_List.h"), ";") {
+		if matches := mdbRE.FindStringSubmatch(line); matches != nil {
+			data.MDB = regexp.MustCompile(`}\s*//`).ReplaceAllString(matches[1], `}, //`)
+		}
+		if matches := configRE.FindStringSubmatch(line); matches != nil {
+			data.DefaultConfigs[matches[1]] = matches[2]
+		}
+	}
+
+	for _, line := range definitions(filepath.Join(base, "P1AM.cpp"), ";") {
+		if matches := caseRE.FindStringSubmatch(line); matches != nil {
+			data.Configs = append(data.Configs, struct{ ID, Name string }{
+				ID:   matches[1],
+				Name: matches[2],
+			})
+		}
+	}
+
+	for _, line := range definitions(filepath.Join(base, "defines.h"), "\n") {
+		if matches := defineRE.FindStringSubmatch(line); matches != nil {
+			data.Defines = append(data.Defines, struct{ Name, Value, Comment string }{
+				Name:    matches[1],
+				Value:   matches[2],
+				Comment: matches[3],
+			})
+		}
+	}
+
+	var buf bytes.Buffer
+	if err := tmpl.Execute(&buf, &data); err != nil {
+		log.Fatal(err)
+	}
+	formatted, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Printf("failed to compile %s", buf.Bytes())
+		log.Fatal(err)
+	}
+	if err := ioutil.WriteFile("defines.go", formatted, 0666); err != nil {
+		log.Fatal(err)
+	}
+}